View Sample Alloy Digest Data Sheet (PDF)Since 1952, Alloy Digest has been the leading reference for materials property data on metals and alloys used throughout the world. Featuring graphs, charts and tables, these sheets give facts and figures on composition or characterization, physical and mechanical properties, heat treatment, and machinability.PYROTOUGH 78 is a hot work die steel possessing a high degree of purity, homogeneity and microstructural integrity that produces a good combination of toughness and temper resistance. The alloy is covered under U.S. Patent No. 4,886,640.